From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A75CBC433DB for ; Thu, 4 Feb 2021 14:12:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C84C64F3F for ; Thu, 4 Feb 2021 14:12:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236582AbhBDOLw (ORCPT ); Thu, 4 Feb 2021 09:11:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236561AbhBDOJ7 (ORCPT ); Thu, 4 Feb 2021 09:09:59 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64113C061573 for ; Thu, 4 Feb 2021 06:09:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=i1MPwPYOiK9y8hJMDgjpJkrCuHMOJ4Dqv8dooOfnSUU=; b=qRnb09mnJWHdMudVWlQSM+eyL BlIiZICfgOsGu7TzHIntTySTyhKwjv98nlDIzg2IDwf44u2rG6klb0mXNBcpI4O2olpa1GFvMJtiI Ate7w82p2oWvVUCInNETA+AvLFyBGL+XTTv7SdBnv3i3GJAp/zk+8na+c02Iku12QhfBLFd699LGu gvK+YZ9k8MKXJulqj8DXgmXHqiLD6Zakjo204lgBSUUcjroFA6kakm8Sx4UrQWlYAWtA/npdDJbA+ ZUgSrF9NlNGnMTzKyLF0q5mQPjSkHDrLJN/gwA/Lu613FTuG46ou7wGl/3ixOEB8jdAqSDgNxZAMb SB6m2xiIQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:39106) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l7fJp-0006cj-Si; Thu, 04 Feb 2021 14:09:13 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1l7fJn-0005EJ-E9; Thu, 04 Feb 2021 14:09:11 +0000 Date: Thu, 4 Feb 2021 14:09:11 +0000 From: Russell King - ARM Linux admin To: Marc Zyngier Cc: Ard Biesheuvel , Guillaume Tucker , Geert Uytterhoeven , Linux Kernel Mailing List , Linus Walleij , Linux ARM , Nicolas Pitre , kernelci-results@groups.io Subject: Re: next/master bisection: baseline.login on rk3288-rock2-square Message-ID: <20210204140911.GX1463@shell.armlinux.org.uk> References: <601b773a.1c69fb81.9f381.a32a@mx.google.com> <6c65bcef-d4e7-25fa-43cf-2c435bb61bb9@collabora.com> <20210204100601.GT1463@shell.armlinux.org.uk> <20210204104714.GU1463@shell.armlinux.org.uk> <090003e6f825de1f8460c0e987e14577@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <090003e6f825de1f8460c0e987e14577@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King - ARM Linux admin Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 04, 2021 at 12:26:44PM +0000, Marc Zyngier wrote: > I agree. With set/way CMOs, there is no way to reach the PoC if > it beyond the system cache, leading to an unbootable kernel. > This is actually pretty well documented in the architecture, > and it did bite us for the first time on XGene-1, 7 years ago. That may be, however we still do set/way maintenance to invalidate the L1 cache as that is required for ARMv7 to place the cache into a known state, as stated by the architecture reference manual. Arguably, that should be done by firmware, but when starting secondary CPUs, there are platforms out there which do not bring the L1 cache to a defined state. So we are pretty much stuck with doing set/way operations during CPU initialisation in the main kernel. If ARMv8 decides that this is not supportable, then that's a matter for ARMv8 to address without impacting the requirements of ARMv7. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!